Algodoo

A Linkage Collision Engine.
It can work both ways, but it works better clockwise.
Drag the propeller to start. It is there to limit the crankshaft speed, because if it goes faster than 116 rad/s, two of the pistons explode at the same time. Although, it seems to have the same strenght and speed with 2 cylinders. (Go ahead and make the test: deactivate air friction and accelerate).
Maybe I will make a new car, if it has the necessary strenght.